High-Precision UAV Surveying in the Mourne Mountains
2026
High-Precision UAV Surveying in the Mourne Mountains
Case Study: Mourne Mountain Aerial Survey
Client: Arup
Background
Malcolm Hughes were appointed to deliver a comprehensive topographic and aerial survey within the Mourne Mountains region in Northern Ireland for a client operating in the outdoors recreation sector. The survey was commissioned to support the design of a proposed gondola system, and its surrounding access routes with deliverables to include orthophotos, a 3d mesh model of a rock face, and traditional topographic drawings. To meet the project's demanding specification and complete the scope of works within a challenging environment our team utilised UAVs in addition to more traditional techniques.
This involved deploying a large UAV with a LiDAR payload to achieve a dense grid of points (3d pointcloud) across the steep vegetated terrain. This was underpinned by the installation and observation of ground-based survey control to confirm absolute accuracy was in line with the client's specification,. Over a three-day period, our surveyors conducted 34 individual flights, collecting high-quality data using our DJI Zenmuse L2 LiDAR sensor and our DJI Zenmuse P1 45MP camera.
The Mourne Mountains are the highest and most dramatic mountain range in Northern Ireland, situated in County Down. This sweeping range of peaks is recognised as both an Area of Outstanding Natural Beauty and a UNESCO Global Geopark. The range is home to Slieve Donard, the tallest mountain in Northern Ireland, which provides expansive views reaching as far as the Isle of Man on clear days .
Deliverables included:
- Detailed topographic plans in 2D and 3D
- High-density 3D point cloud data
- 3D mesh model of the quarry rock face
- Orthophotos and high-resolution aerial imagery
The survey was successfully delivered to specification, providing robust, reliable, geospatial data to inform future development considerations.
Challenges
The project involved several technical, environmental, and regulatory constraints.
Technical & Line‑of‑Sight Issues
- The 4km access routes passed through dense forest and steep terrain, limiting UAV line of sight.
- Despite LiDAR use, detailed features (gulleys, manholes, culverts) still required traditional ground surveying.
Operational Complexity
- On-site checks revealed reduced visibility not evident pre‑mobilisation, requiring additional UAV flights for full coverage.
Regulatory & Safety Constraints
- Compliance with CAA 120m/400ft flight‑height limits meant elevation points had to be surveyed traditionally before flying.
- Terrain-following mode was avoided to maintain visual line of sight over steep, forested areas.
Environmental Conditions
- The exposed mountain/coastal setting produced challenging weather; flights were scheduled during suitable windows.
Tools & Technology
A hybrid approach combined UAV and traditional surveying to ensure accuracy and compliance.
UAV Hardware
- DJI Enterprise platform (RTK)
- Zenmuse L2 LiDAR (penta-return)
- Zenmuse P1 45MP photogrammetry camera
Solutions
- Ground surveying of access tracks to capture detail not visible from UAVs
- Ground control network to maintain LiDAR accuracy
- Limited terrain-follow use to ensure safe line of sight
- Adaptive flight planning based on real terrain conditions
- Extra flights added after reconnaissance
- Weather‑responsive scheduling to maximise productivity
This combined method demonstrates the flexibility and precision of our UAV Surveying and Mapping services:
https://www.malcolmhughes.co.uk/services/uav-surveys/
Summary
Client Benefit
This project was delivered with a clear focus on providing accurate, reliable, and design-ready survey data in a complex mountain environment. By combining advanced UAV technology with traditional surveying techniques, the approach reduced risk, improved efficiency, and ensured the client could progress design and planning with confidence and certainty.
- Robust, design-ready data – providing a reliable foundation for informed design decisions, reducing uncertainty and the risk of late-stage redesign.
- Guaranteed accuracy and reliability for immediate use of data without further verification.
- Comprehensive coverage of challenging terrain delivering a complete and consistent dataset.
- Diverse, fit for purpose deliverables A full suite geospatial outputs supported multiple disciplines.
- Operational efficiency in complex environments, maintaining programme momentum despite difficult terrain and limited weather windows.
- Regulatory and safety compliance adhered to protecting the client, reducing project risk, and avoiding regulatory delays.
To speak with our specialist, please get in touch here, let us know how we can support on your next project. Read more about our UAV services here.
